Voltcraft VC-SPB-20.000 Operating Instructions Manual

The Voltcraft VC-SPB-20.000 is a precision laboratory power supply unit offering a maximum output of 20V and 20A, with high stability and low ripple for demanding electronic applications. It features adjustable voltage and current, multiple protection circuits (OVP, OCP, OTP), remote sensing, serial interface for PC control, and a robust design for bench use. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Front panel with digital displays, adjustment knobs, output terminals, Remote Sensing terminals, and communication port.

Installation

Unpack and inspect contents. Place on a stable, well-ventilated bench surface.

1. Connect AC Power: Use the supplied power cord to connect to a grounded mains outlet.
2. Connect Load: Attach load cables to the + (red) and - (black) output terminals. Ensure correct polarity.
3. Remote Sensing (Optional): For precise voltage at the load, connect sense leads directly to the load points.
4. Communication (Optional): Connect the RS-232 or USB cable to a PC for remote operation.

WARNING! Ensure proper ventilation. Do not block cooling vents. Use appropriate wire gauge for high-current applications.

First-Time Setup

Power on the unit; observe the display initialization.

1. Set Output Voltage: Turn the VOLTAGE knob to the desired level (0-20V).
2. Set Current Limit: Turn the CURRENT knob to the desired maximum current (0-20A).
3. Enable Output: Press the OUTPUT ON/OFF button. The output indicator should light up.
4. Verify Mode: The display will indicate CV (Constant Voltage) or CC (Constant Current) based on the load.
5. Remote Interface: Install the provided PC software and configure communication settings if used.

CAUTION! Always set the voltage and current limits before connecting a sensitive load. Start with the current limit at a low value.

Specifications

• Output Rating: 0-20 V DC, 0-20 A DC.
• Line Regulation: < 0.01% + 2mV.
• Load Regulation: < 0.01% + 3mV (CV), < 0.2% + 3mA (CC).
• Ripple & Noise: < 1 mVrms (CV), < 3 mArms (CC).
• Display Resolution: 10 mV / 10 mA.
• Display Accuracy: ±(0.5% of reading + 2 digits).
• Protections: Over Voltage (OVP), Over Current (OCP), Over Temperature (OTP).
• Interface: RS-232 / USB (isolated).
• Power Source: 100-240V AC, 50/60Hz.
• Operating Temp: 0°C to 40°C.

Controls and Settings

All primary controls are located on the front panel.

Front Panel: POWER switch, VOLTAGE knob, CURRENT knob, OUTPUT ON/OFF button, MODE button, Voltage/Current displays.

Operation: In CV mode, the unit regulates voltage; current is determined by the load. In CC mode (triggered when load exceeds set current limit), the unit regulates current; voltage drops. Use the MODE button to view the active mode. The OVP level can be set via a combination of front panel buttons (see full manual). Remote sensing compensates for up to 0.5V drop per lead.

Connecting Devices

Load Connection: Use the main output terminals. Remote Sensing: Connect sense leads to the remote sense terminals and directly to the load.

1. Turn off the OUTPUT and the unit before making connections.
2. For two-wire operation, connect only the main output leads.
3. For four-wire (remote sense) operation, connect the sense leads in parallel with the output leads, directly at the load.
4. Select the correct input on the connected device (e.g., correct voltage polarity on a PCB).

Tip: Use twisted-pair or shielded cables for remote sensing to minimize noise pickup.

Operation Modes

Supports Constant Voltage (CV) and Constant Current (CC) operation.

1. Constant Voltage (CV): Default mode. Set voltage with knob. Current display shows actual load current.
2. Constant Current (CC): Activated automatically if load attempts to draw more than the set current limit. Voltage drops to maintain the set current.
3. Output Enable/Disable: Use OUTPUT button. Disabling turns voltage/current to zero but retains settings.
4. Memory Recall: Some models can store and recall frequently used voltage/current settings.
5. Remote Control: Via PC software using SCPI commands or provided GUI.

WARNING! Do not short the output terminals. Even in CC mode, a short circuit will cause the unit to deliver the full set current, which can generate heat.

Protection Features

Over Voltage Protection (OVP): User-settable threshold. If exceeded, output shuts off. Over Current Protection (OCP): Limits current to the set value (CC mode). Over Temperature Protection (OTP): Internal; shuts down unit if overheated.

Care & Cleaning

Disconnect from AC power before cleaning. Use a soft, dry cloth only. Do not use liquids, solvents, or compressed air inside the unit.

CAUTION! Ensure the unit is completely disconnected from mains and any connected load before cleaning. Keep away from dust and moisture.

Regulatory Information

CE Compliant: Meets EU safety and EMC directives. Designed and tested according to relevant IEC standards. Copyright © by Voltcraft. For support, visit www.conrad.com or contact the Conrad International technical support line. This device is intended for professional, commercial, or industrial use in a laboratory environment.

Troubleshooting

Reset: Power cycle the unit. For persistent issues, a factory reset may be available via a hidden menu (consult full manual).

Service: Contact authorized Voltcraft service center. Do not open the unit; internal components carry hazardous voltages.